<PRE><B>Question 419429</B>
Find exact value for given trig fuctions of an angle (measured in degrees and radians)
A) Sin495°
B) Cos810
C) tan18pi/6
D) Cos 13pi/4
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A) sin 495 deg
495-360=135 which is a 45 deg reference angle in quadrant II
ans:sin 495 deg = sqrt(2)/2
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B)cos 810 deg
810-720=90 deg reference angle
ans:cos 810=0
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C)tan18pi/6
18pi/6=3pi=pi reference angle
ans:tan18pi/6=0
..
D) Cos 13pi/4
13pi/4=pi/4 reference angle in quadrant I
ans:Cos 13pi/4=sqrt(2)/2

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